MECHANISTIC INVESTIGATION OF Pd(II)-CATALYSED OXIDATION OF MALTOSE BY CHLORAMINE-T IN ACIDIC MEDIUM. A KINETIC STUDY

The kinetics of Pd(II)-catalysed oxidation of D-maltose by acidic solution of chloramine-T in the presence of mercuric acetate, as a scavenger have been made in the temperature range of 30-45 degrees C.The oxidation product is maltobionic acid. The reaction is of first order in case of chloramine-T and Pd(II) both and order of reaction is zero with respect to maltose. The reactin shows less than unit order in case of [Cl-], while rate of reaction shows zero effect in case of [H+]. Negligible effect of mercuric acetate and ionic strength of the medium was observed. A transient complex, formed between PdCl2 and chloramine-T. PdCl2 being the reactive species of palladium(II) chloride, disproportionates in a slow and rate-determining step. Various activation parameters with respect to slow step of the mechanism are computed and discussed. A suitable mechanism in agreement with the observed kinetics has been proposed.